Manufacture of air-heating elements



Oct. 26 1926.

C. W. EpCLARKE MANUFACTURE, 0F AR HEATING ELEMENTS- Filed Nov. 15, 1924 4 Sheets-Sheet 1 INVENTOR 6i w. 6m

Oct. 26 1926.

C. W. E. CLARKE v MANUFAGTURE OF AIR HEATING ELEMENTS 4 Sheets-Sheet 2 Filed Nov. v15. 1924 INVENTOR @gp/[66 642W@ W ATI'ORNE Oct 26 ,'1926.

. c. w. E. CLARKE MANUFACTURE oF MR "HEATING ELEMENTS 4 Sheets-Sheet 3 Filed Nov. 15, 192:4`

40 INVENTOR 611./ 5. 6M@ Y I@ e Y A ATTORNEYS 0st. 26 1926. I 1,604,259

c. w.. E. CLARKE MANUFACTURE 0'1" AR HEATING ELEMENTS Filed Nov. 15. 1924- Sheets-Sheet 4 INVENTOR Patented @et 'i926 unirse MANUFACTURE OF AIR-EIEATNG ELEMENTS.

Original application filed March il, 1924, Serial No. 698,405. Divided and. this application led November' 15, 1924.

My invention relates to the manufacture of air heating elements. and has special reterence to blanks for heating` elements and to a method of constructing' and assembling' the blanks. A heating element of the type to which. the invention relates particularly comprises two plates ot sheet metal arranged side by side and spaced apart with their edges welded together, means being provided tor directing air to be heated through the si ace between the plates.

An object ot the invention is to provide blanks ot novel and improved construction tor air heating' elements ot this character.

Another object ot the invention is to provide a novel and improved method of torminp; the blanks.

Another object of the invention is to provide a novel and improved method ot constructing' a heating element ot the character indicated.

The several features of the invention, whereby the above mentioned and other ol jects may be attained. will be clear y underw stood trom the following description and accompanying' drawings. in which:

Figure 1 is a front elevation partly in section, ot an air heating apparatus embodying; air heating' elements constructed in accordance with my invention. the apparatus being' shown inserted in the uptake flue of a furnace;

Fin?. 2 is a detail side elevation of one of the air heating' elements;

Fig. S is a sectional view, on an enlarged scale, taken on the line 3mi? of Fig. 2;

Figs. 1 and 5 are detail sectional views taken on the lines 4 4 and 5-5, respectively. ot Fig. 2;

Figs. 6 and 7 are detail views in perspective of component parts oit the air heating element;

8 is a view similar to Fig'. 2 of a modified construction ot heating; element;

Fin'. 9 is a sectional view taken on the line 9-9 of Fig'. 8, showingc a plurality ot the heating' elements assembled;

Figs. 10 and 11 are sectional views on an enlarged scale taken on the lines 10-10 and l1 11 ot Fig'. 14.-;

Figs. 12 and 13 are detail views in perspective of component parts of the heating element illustrated in Fig. 8;

Fig'. 14 is a view in perspective of one of the plates oi the hec-,tingelement illustrated in Fig. 2 5 and Serial No. 750.079.

Fig. 15 is a similar view of one of the plates ot the heating element illustrated in Fig. 8.

rlhe air heating apparatus illustrated in Fiir. 1 oi the drawincjs is oit' the type. oi' the one described and claimed in my pending' application Serial No. 698,405. iiled March 11. 1924. ot which the present application is a division. As shown. the air heatinfr apparatus is provided with a casino; which is arranged vertically and has its lower end connected with header which may lead from the flue gas outlet ot a boiler Vfurnace. and has its upper end connected with a header 4 which may lead to the furnace chimney. rllhis casino' .is provided with front and rear walls 6 and 8. respectively. and with side walls 10. The casingis divided by partitions 12 into two air heating; sections 14C and 16 having a gras by-pass 18 between them which is adapted to be opened and closed by means ot a damper 20. Each ot' the side walls 10 of the casing is provided with an air inlet openingP 22 which may be open to the atmosphere or may be connected by a conduit with a source oi air supply. and is further provided with an air outlet opening' 26 which may be suitably connected by a conduit 2S with the wind boi: ot the fur4 nace. Each of the air heating' sections 14 and 1G contains a plurality ot' air heating elements 30 arranged vertically side by side and spaced apart and extending" between the side wall 1() of the heating; section and the partition or wall 12. Flach air heatingr element comprises two plates 32 and 34C (Figs. 2 and 3) that are arranged side by side and spaced apart. Each ot the elements is provided with an air inlet opening' 36 and an air outlet opening' 38. the air inlet and outlet openings oi the several `elements in each heating' section being' in communication with the air inlet and outlet openings 22 and 26, respectively, of the section. Flach air heating element is divided into a plurality ot passages extending' between the inlet and outlet openings thereof by means ot' suitably arranged angle irons 40 secured to one of the plates. The several heating' elements of each heating section are held spaced apart to provide gas passes between them by means oi' vertically arranged angle irons 42 that are welded or otherwise secured to one of the plates of each heating element.

The modified construction of air heating element illustrated in Figs. 8 and 9 comprises two plates 32 and 34 that like plates 32 and 34 are arranged si-de by side and spaced apart. rlllhis element also is provided with inlet and outlet openings S6 and 38', angle irons 40 secured on the inside side ot one of the plates, and angle irons 4?/ secured on the outside of the plate 32', which parts may be the same as the. corresponding` parts of the air heating element first described.

The parts above referred to may be and preferably are the same as the corresponding parts of the air heating apparatus illustrated and described in my pending application hereinbefore referred to, to which r reference may be had for a full and complete description of the same.

ln accordance with the present invention, in constructing each plate of the air heating el-ement illustrated in Fig. Q, a substantially fiat sheet is provided which is cntto form a substantially rectangular body portion, Fig. i4, havingl one of its longitudinal edges provided with two projecting marginal portions adjacent the encs thereof forming flanges 44, the upper project-ing portion or flange having its up 3er end spaced a slight distance 4from the upper edge of the body ot' the plate, the lower projecting` portion or flange having its lowerend spaced a slight distance Jfrom the lower edge ot the hotly portion, and the inner ends of said .fi'ojecting portions or flanges being spaced a distanceapart. rl`he inner longitudinal portion of `each of said portions or flanges 44 are bent to form the inclined portion 46, and the outer portion 48 which is arranged parallel with the body of the plate. The. ends of the central marginal portion 50 between t-he inner ends of said flanges 44 are slitted at 52. and this central marginal portion is bent in 'the opposite direction to the inclined portions 46 of the flanges 44. rl`he opposite corners of the plate at the ends ot the other longitudinal edge are provided with diagonal slits 54, and the marginal portion of this longitudinal edge and the marginal portions ot the ends of the body of the plate are bent in the same direction as said central marginal portion 50. rllhe slits 54 are of suitable shape so that when the marginal portions ot the latter longitudinal edge and the ends of the plate are bent, the edges of the adjacent ends thereof are brought together. These edges are then welded, which completes the formation ot the plate. lt may be noted that both of the plates of the air heating element illustrated in Fig. 2 are constructed in the manner above described and are interchangeable.

The two plates are assembled to form the heating element after the angle irons 40 have been applied to one ci" them, as hereinbeiore described, by bringing the plates together with the edges of th-e inwardly bent marginal portions of the plates positioned in engagement, and then welding these edges together.

fllie upper flanges 44 of each air heating element forms the air inlet opening 3G thereot, and the lower flanges 44 thelair outlet opening 38. rlfhe spaces at the upper and lower outer corners ot each heating element formed by the outwardly turned flanges 44 are closed by castings 56 of suitable shape to permit them to be inserted between the plates, and the spaces between the inner ends of the flanges 44 of each pair are closed by suitably shaped castings 58. '.he castings and 58 are welded to the plates so as to form air tight joints.

The plate 82 ot the modified construction of heating element illustrated in Figs. 8 and 3 is flat throughout its area and the body portion thereof is substantially rectangular. @ne ot' 'the longitudinal edges of the body portion of this plate. 3a is provided with two projecting marginal portions or flanges (30, the upper end ofthe upper flange being spaced a slight distance from the upper end of the plate andthe lower end of the lower flange being spaced a slight distance from the lower end of the plate. rllhe plate 34 corresponds substantially in contour to the plate 32. The flanges 44 ot' the plate 34', which correspond to the flanges GO of' the plate 32 are bent outwardly as shown to provide an outwardly inclined portion 46 and a portion 48 in a plane parallel to the plane of the body of the plate. The margins of the portion 50 of the plate 34 between the flanges 44', the end margins of the plate. and the margin of the other longitudinal edgeof the plate are bent inwardly at an angle` rlhe opposite corners of the plate 34 at the ends of the other longitudinal edge are provided with diagonal slits 54', and lthe marginal portions ot the ends of the body of the plate are bent in the same direction as said central marginal portion, the slits 54 beine; of suitable shape so that when the marginal portions of the latter longitudinal edge and the. ends of the plate are bent, the edges of adiacent ends thereofl brought together. These end edges are ythen welded which completes the formation of the plate;

The two plates 32 and 34 are assembled to form the heating element atter the angle irons 40 have been applied to one of them as hereinbefore described, by bringing the plates together with he edges ot the inwardly bent ma inal. portions of the plate 34 positioned in engagement with the corresponding edge portions of the plate 32', and then welding` these engaging edge portions of the rtwo plates together. The openings at the upper and `lower outer corners formed by the flanges 60 and 44 are closed by castings 56 of suitable shape to permit lit) them to be inserted between the plates., and the spaces between the inner ends of said flanges of each pair are closed by suitable shape castings 5S. rllhe castings 56 and 58 are welded to the plates so as to form air tight joints. lt may be noted that the plate 234i is constructed in the saine manner as each ot the plates ot' the air heating first described except that in the former the bent marginal portions and also the flanges dat are wider than the corresponding parts of the latter plates. i

As will be evident to those skilled in the art, my invention permits various modifications without departing from the spirit thereof or the scope ot the appended claims.

ldlhat I claim is:

l. A blank for an air heating element ot the class described comprising a substantially rectangular flat plate having marginal portions of its ends, one of its longitudinal edges, and the central portions of its other longitudinal edge bent in one direction from the body ot the plate, and the marginal portions ot the last mentioned longitudinal edge between the ends of said central marginal portion and the ends oit the body of the plate bent in the opposite direction.

2. A blank for an air heating' element of the class described comprising a plate having a substantially flat rectangular body portion having one of its longitudinal edges provided with projecting flanges adjacent the ends ofI the pla-te` each of said flanges being bent so that its inner longitudinal portion is transversely inclined in one direction to the body of the plate and its outer longitudinal portion is arranged substantially parallel with the body of the plate, and having the marginal portions of the other longitudinal edge and the ends ot the plate bent transversely in the opposite direction.

3. A. blank i'or an air heating element of the class described comprising a substantially rectangular flat plate having marginal portions ot its ends, one of its longitudinal edges and the central portion ot its other longitudinal edge bent in one direction from the body of the plate, and havingdiagonally extending slits in the corners et the plate at the ends of said longitudinal edge to enable the edges of adjacent ends ot said marginal portions at said corners to be brought together, the portions of the other longitudinal edge of the plate between the ends of said central portion and the ends of the plate being bent in the opposite direction.

1l. A blank tor an'air heating element of the class described comprising a substantially rect-angular flat plate having marginal portions ot its ends, one of its longitudinal edges and the central portion oi its other longitudinal edge bent in one direction Jfrom the body et the plate, and having diagonally extending slits in the corners of the plate at the ends of said longitudinal edge to enable the edges of adjacent ends of said marginal portions at said corners to be brought together, said edges being welded, and the portions of the other longitudinal edge of the plate between the ends of said central portion and the ends of the plate being bent in the opposite direction.

5. rll`he method of forming a blank for an air heating element of the class described which comprises cutting a metal sheet so as to form a substantially rectangular plate, bending in one direction the marginal portions ot its ends, one of its longitudinal edges, and the central portion of its other longitudinal edge, and bending in the opposite direction the marginal portions of the second mentioned longitudinal edge between said central portion and the ends of the plate.

6. The method of forming a blank for an air heating element -o' the class described which comprises cutting a substantially rectangular plate from a fiat sheet of metal, diagonally slitting opposite corners of' the plate at the ends ot one of the longitudinal edges thereof, bending in one direction the marginal portions of said longitudinal edge and the marginal portions of the ends of the plate so as to bring adjacent ends of said longitudinal and said end marginal portions together', welding said adjacent ends, bending in the same direction the central portion of the other longitudinal edge of the plate, and bending in the opposite direction the marginal portions of said second mentioned longitudinal edge of the plate between the ends of said central portion and the ends of the plate.

7. rl`he method of constructing an air heating element ot the class described `which comprises cutting a sheet of metal so as to form a substantially rectangular flat plate, bending in one direction the marginal portions olf one of the longitudinal edges, the ends, and the central porti-on of the other longitudinal edge oit' the plate, and bending in the opposite directions the marginal portions ofi the second mentioned longitudinal edge oi" the plate between said central portion and the ends of the plate, forming a second plate of substantially the size and contour of said first mentioned plate, applying it so as to bring the edges thereof into engagement with the edges of said iirst mentioned bent marginal portions, and welding said engaging edges together.

CHARLES lV. E. CLARKE. 

